我希望 \edef 能起作用

Question

我想生成一个名为“anglelist生成图表”的列表...对我来说，首选的命令是，\edef\anglelist{\fullanglelist}但却出现了错误。

但使用\edef\anglelist{\fullanglelist}和\edef\anglelist{\fixedlist}不会给我任何错误。

我的问题是“你能告诉我该如何工作吗\edef\anglelist{\fullanglelist}？

先谢谢了。接下来请看一下我所说的代码。

\documentclass[11pt]{article}
\usepackage{tikz}
\begin{document}

\newcount\nodes
\nodes=8

\newcount\hnodes
\hnodes=\nodes
\advance \hnodes by -1
\divide \hnodes by 2
%
\newcount\hnodesplus
\hnodesplus=\nodes
\advance \hnodesplus by 1
\divide \hnodesplus by 2
%
\newcount\initialstepsize
\initialstepsize=360
\divide \initialstepsize by \nodes
%
\newcount\initialremainder
\initialremainder=\initialstepsize
\multiply \initialremainder by -\nodes
\advance \initialremainder by 360
%
\newcount\hstep
\hstep=\initialstepsize
\divide \hstep by 2

\newcount\simplestep
\simplestep=\initialstepsize
\ifnum \initialremainder > 0%this makes angles a larger than expected. 
\advance \simplestep by 1
\fi



\def\fullanglelister{%
\newcount\tempa
\newcount\tempb
\tempa=0
\tempb=0
%
\loop
\the\tempa\relax
\advance\tempa by \initialstepsize
\advance\tempb by \initialremainder
\ifnum\tempb > \hnodes% usually chosen to be 0, (better to be) \hnodes, or \nodes 
\advance\tempa by 1
\advance\tempb by -\nodes
\fi
\ifnum \tempa < 360
,
\repeat}


\def\shortanglelister{0, \the\simplestep, ..., 359}
\def\fixedlist{0, 45, 90, 135, 180, 225, 270, 315}

\edef\anglelist{\shortanglelister}
%\edef\anglelist{\fullanglelister} % this one doesn't work!
%\edef\anglelist{\fixedlist} % but this works!

\begin{tikzpicture}
  \foreach \angle in \anglelist
\node[rectangle,draw=black!50] (\angle) at (\angle:2) {\angle};

\foreach \from in \anglelist
\foreach \to in \anglelist
\path (\from) edge [->,bend right=\the\hstep,looseness=0.8] (\to);
\end{tikzpicture}


\fullanglelister
\shortanglelister
\fixedlist

\end{document}

Answer 1

如果（出于某种原因）您想扩展 edef 中的循环，则需要使用扩展而不是使用赋值来编写它。以下代码扩展为

0, 45, 90, 135, 180, 225, 270, 315

如 typeout 行所示

B: 0, 45, 90, 135, 180, 225, 270, 315

在控制台上

\documentclass[11pt]{article}
\usepackage{tikz}
\begin{document}

\newcount\nodes
\nodes=8

\newcount\hnodes
\hnodes=\nodes
\advance \hnodes by -1
\divide \hnodes by 2
%
\newcount\hnodesplus
\hnodesplus=\nodes
\advance \hnodesplus by 1
\divide \hnodesplus by 2
%
\newcount\initialstepsize
\initialstepsize=360
\divide \initialstepsize by \nodes
%
\newcount\initialremainder
\initialremainder=\initialstepsize
\multiply \initialremainder by -\nodes
\advance \initialremainder by 360
%
\newcount\hstep
\hstep=\initialstepsize
\divide \hstep by 2

\newcount\simplestep
\simplestep=\initialstepsize
\ifnum \initialremainder > 0%this makes angles a larger than expected. 
\advance \simplestep by 1
\fi



\makeatletter
\def\fullanglelister{%
\expandafter\@gobble\romannumeral`\^^@%
\expandafter\zz\shortanglelister\relax}
\def\zz#1,#2,#3,#4\relax{%
\ifnum#1<\numexpr#4\relax
, \the\numexpr#1\relax
\expandafter\zz\the\numexpr#1+#2\relax,#2,#3,#4\relax
\fi}
\makeatother

\def\shortanglelister{0, \the\simplestep, ..., 359}
\def\fixedlist{0, 45, 90, 135, 180, 225, 270, 315}

\edef\anglelist{\shortanglelister}
\typeout{A:\anglelist}
\edef\anglelist{\fullanglelister} % this one does work!
\typeout{B:\anglelist}
%\edef\anglelist{\fixedlist} % but this works!

\begin{tikzpicture}
  \foreach \angle in \anglelist
\node[rectangle,draw=black!50] (\angle) at (\angle:2) {\angle};

\foreach \from in \anglelist
\foreach \to in \anglelist
\path (\from) edge [->,bend right=\the\hstep,looseness=0.8] (\to);
\end{tikzpicture}


\fullanglelister
\shortanglelister
\fixedlist

\end{document}

Answer 2

如果您希望整数尽可能均匀地朝着特定目标移动，最好的方法是在每次迭代时重新计算步长，即剩余距离除以剩余步数。

通常的做法是将 的结果放入\edef与创建它的宏不同的宏中。例如， 的输出\pgfmathparse放入\pgfmathresult，并\pgfmathsetmacro接受输出宏名称作为参数。这是我采取的方法。

\documentclass[11pt]{article}
\usepackage{tikz}

\newcount\nodes% considering how infrequently this is used, a macro would suffice

\def\fullanglelister#1{% #1 = output macro name (global)
\bgroup% use local registers
  \count1=0 % angle
  \count2=\nodes% remaining steps
  \edef\temp{\the\count1}% output macro (local)
  \loop
    \count3=360 % compute step size (360-angle)/steps
    \advance \count3 by -\count1
    \divide \count3 by \count2
    \advance\count1 by \count3
    \advance\count2 by -1
    \edef\temp{\temp,\the\count1}%
  \ifnum \count2>1 \repeat
  \global\let#1\temp
\egroup}

\begin{document}

\nodes=8
\fullanglelister{\anglelist}%
\pgfmathsetmacro{\hstep}{360/\nodes}%

\begin{tikzpicture}
  \foreach \angle in \anglelist
\node[rectangle,draw=black!50] (\angle) at (\angle:2) {\angle};

\foreach \from in \anglelist {
  \foreach \to in \anglelist {
    \path (\from) edge [->,bend right=\hstep,looseness=0.8] (\to);}}
\end{tikzpicture}

\end{document}